readme: fix status badge

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

README.md

@@ -2,7 +2,7 @@
 
 [![GitHub release](https://img.shields.io/github/release/docker/buildx.svg?style=flat-square)](https://github.com/docker/buildx/releases/latest)
 [![PkgGoDev](https://img.shields.io/badge/go.dev-docs-007d9c?style=flat-square&logo=go&logoColor=white)](https://pkg.go.dev/github.com/docker/buildx)
-[![Build Status](https://img.shields.io/github/workflow/status/docker/buildx/build?label=build&logo=github&style=flat-square)](https://github.com/docker/buildx/actions?query=workflow%3Abuild)
+[![Build Status](https://img.shields.io/github/actions/workflow/status/docker/buildx/build.yml?branch=master&label=build&logo=github&style=flat-square)](https://github.com/docker/buildx/actions?query=workflow%3Abuild)
 [![Go Report Card](https://goreportcard.com/badge/github.com/docker/buildx?style=flat-square)](https://goreportcard.com/report/github.com/docker/buildx)
 [![codecov](https://img.shields.io/codecov/c/github/docker/buildx?logo=codecov&style=flat-square)](https://codecov.io/gh/docker/buildx)